Hi guys, I've had this laptop since Summer 2016 and finally fixed the thermal throttling after taking a long hard look at the problem again (just always gamed on my desktop). I thought I'd help the community out with a short tutorial (was active back in the days of the Alienware m11x and helped troubleshoot that device)

Issue:

I believe the main issue is not due to heat. I've read countless threads on here and Reddit pointing to the VRM getting too hot, and thus causing throttling, which I don't think is the main cause.
EDIT:

What I'm saying is:
Main cause of CPU throttling is DPTF because of high VRM temps, which are hard to cool so we disable DPTF
Main cause of GPU throttling are GPU temps (influenced by overall ambient temps, including CPU temps)

Click to expand...

Instead, with demanding use of both cpu and gpu (issue is 100% reproducible in Overwatch, which are many of the complaints online), Intel Dynamic Platform and Thermal Framework will limit the TDP usage of the laptop to around 6-7W, which keeps the cpu clocks to a locked 800mhz. This is apparent as Throttlestop reported PL1 and PL2 causing the throttle under Limit Reasons, which will look something like this (I found this image online, not for my laptop fyi):

While playing Overwatch in exclusive fullscreen mode, framerates remain well. However, while playing in borderless fullscreen mode, I believe with the increased stress in having to process the Windows desktop, thermal throttling occurs, and the clock speed/TDP will steadily drop until 6-7W/800mhz and remain there until Overwatch is closed.

I believe that before a GPU repaste, my 960m was getting throttled as well, but not sure if it was the repaste that fixed that issue or driver updates etc.

My only concern is that if you didn't do a good repaste and VRM padding you have a chance to actually damage some components. I am reasonably confident in my paste job and temps (plus I use TS to keep temps under control) but if you did this on a totally stock XPS 15 I reckon you'd fry something.

Very important:
Disabling Turbo while gaming will keep temperatures down and keep the GPU from thermal throttling as well

You don't need your cpu turboed at 3.2ghz, 2.6ghz is fine. I now have a Throttlestop profile dedicated to disabling Turbo during gaming. Keeping Turbo on will cause the cpu to be 90C+, and my gpu will reach 90C as well and keep throttling, steadily lowering the gpu core clock to compensate. Disabling Turbo keeps my cpu at ~80C, and my gpu at ~87C.

I also applied this, not sure if necessary as well, but I'm going to keep the settings (through Intel XTU, and never opening it again as it can interfere with Throttlestop):http://forum.notebookreview.com/thr...-limit-throttling.793136/page-9#post-10449799
"==> Bumped "turbo boost power max" to 65 watts (from 55 watts). That 65 watts shows up in HWiNFO64 also.
==> Also increased the "turbo boost power time window" to 96 seconds.
==> These settings seem persistent as they stick in registers even after several weeks of shutdowns."

I did install Dell Command Power Manager and set it to Ultra Performance, but I think that's also unnecessary. Thanks @pressing

I also did this (not sure if necessary):
Under Device Manager, under Firmware, right click System Firmware > Update > Search Automatically. Apparently this is supposed to pull the updates from the new BIOS? I've never done this before, but read it somewhere so that's what I did lol.

What I'm saying is:
Main cause of CPU throttling is DPTF because of high VRM temps, which are hard to cool so we disable DPTF
Main cause of GPU throttling are GPU temps (influenced by overall ambient temps, including CPU temps)

I tried to remove DPTF before, but it kept reinstalling itself. Are you sure turning off wifi fixes it permanently? It won't just reinstall immediately?

Click to expand...

Mmhm, DPTF still uninstalled after I've rebooted my computer:

When I was still connected to internet, Windows immediately reinstalled DPTF right after I uninstalled it. Turning off internet prevented this -- Windows Update shouldn't reinstall it either since they're disabled.

My only concern is that if you didn't do a good repaste and VRM padding you have a chance to actually damage some components. I am reasonably confident in my paste job and temps (plus I use TS to keep temps under control) but if you did this on a totally stock XPS 15 I reckon you'd fry something.